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  <title>Prepares an SQL statement for execution</title>
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  <div id="layout-content"><div id="mysqli-stmt.prepare" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">mysqli_stmt::prepare</h1>
  <h1 class="refname">mysqli_stmt_prepare</h1>
  <p class="verinfo">(PHP 5, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">mysqli_stmt::prepare</span> -- <span class="refname">mysqli_stmt_prepare</span> &mdash; <span class="dc-title">Prepares an SQL statement for execution</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-mysqli-stmt.prepare-description">
  <h3 class="title">说明</h3>
  <p class="para">面向对象风格</p>
  <div class="methodsynopsis dc-description">
   <span class="modifier">public</span> <span class="methodname"><strong>mysqli_stmt::prepare</strong></span>(<span class="methodparam"><span class="type">string</span> <code class="parameter">$query</code></span>): <span class="type">bool</span></div>

  <p class="para rdfs-comment">过程化风格</p>
  <div class="methodsynopsis dc-description"><span class="methodname"><strong>mysqli_stmt_prepare</strong></span>(<span class="methodparam"><span class="type"><a href="class.mysqli-stmt.html" class="type mysqli_stmt">mysqli_stmt</a></span> <code class="parameter">$statement</code></span>, <span class="methodparam"><span class="type">string</span> <code class="parameter">$query</code></span>): <span class="type">bool</span></div>

  <p class="para rdfs-comment">
   Prepares a statement for execution.
   The query must consist of a single SQL statement.
  </p>
  <p class="para">
   The statement template can contain zero or more question mark
   (<code class="literal">?</code>) parameter markers⁠—also called placeholders.
   The parameter markers must be bound to application variables using
   <span class="function"><a href="mysqli-stmt.bind-param.html" class="function">mysqli_stmt_bind_param()</a></span> before executing the statement.
  </p>
  <blockquote class="note"><p><strong class="note">注意</strong>: 
   <p class="para">
    In the case where a statement is passed to
    <span class="function"><strong>mysqli_stmt_prepare()</strong></span> that is longer than
    <code class="literal">max_allowed_packet</code> of the server, the returned
    error codes are different depending on whether you are using MySQL
    Native Driver (<code class="literal">mysqlnd</code>) or MySQL Client Library
    (<code class="literal">libmysqlclient</code>). The behavior is as follows:
   </p>
   <ul class="itemizedlist">
    <li class="listitem">
     <p class="para">
      <code class="literal">mysqlnd</code> on Linux returns an error code of 1153.
      The error message means <q class="quote">got a packet bigger than
      <code class="literal">max_allowed_packet</code> bytes</q>.
     </p>
    </li>
    <li class="listitem">
     <p class="para">
      <code class="literal">mysqlnd</code> on Windows returns an error code 2006.
      This error message means <q class="quote">server has gone away</q>.
     </p>
    </li>
    <li class="listitem">
     <p class="para">
      <code class="literal">libmysqlclient</code> on all platforms returns an error code
      2006. This error message means <q class="quote">server has gone
      away</q>.
     </p>
    </li>
   </ul>
  </p></blockquote>
 </div>


 <div class="refsect1 parameters" id="refsect1-mysqli-stmt.prepare-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>
    <dt>

<code class="parameter">statement</code></dt>
<dd>
<p class="para">仅以过程化样式：由
<span class="function"><a href="mysqli.stmt-init.html" class="function">mysqli_stmt_init()</a></span> 返回的 <span class="classname"><a href="class.mysqli-stmt.html" class="classname">mysqli_stmt</a></span> 对象。</p></dd>

    
     <dt>
<code class="parameter">query</code></dt>

     <dd>

      <p class="para">
       The query, as a string. It must consist of a single SQL statement.
      </p>
      <p class="para">
       The SQL statement may contain zero or more parameter markers
       represented by question mark (<code class="literal">?</code>) characters
       at the appropriate positions.
      </p>
      <blockquote class="note"><p><strong class="note">注意</strong>: 

       <p class="para">
        The markers are legal only in certain places in SQL statements.
        For example, they are permitted in the <code class="literal">VALUES()</code>
        list of an <code class="literal">INSERT</code> statement (to specify column
        values for a row), or in a comparison with a column in a
        <code class="literal">WHERE</code> clause to specify a comparison value.
        However, they are not permitted for identifiers (such as table or
        column names).
       </p>
      </p></blockquote>
     </dd>

    
   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-mysqli-stmt.prepare-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   成功时返回 <strong><code>true</code></strong>， 或者在失败时返回 <strong><code>false</code></strong>。
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-mysqli-stmt.prepare-examples">
  <h3 class="title">范例</h3>
  <div class="example" id="example-1507">
   <p><strong>示例 #1 <span class="methodname"><strong>mysqli_stmt::prepare()</strong></span> example</strong></p>
   <div class="example-contents"><p>面向对象风格</p></div>
   <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /><br />mysqli_report</span><span style="color: #007700">(</span><span style="color: #0000BB">MYSQLI_REPORT_ERROR&nbsp;</span><span style="color: #007700">|&nbsp;</span><span style="color: #0000BB">MYSQLI_REPORT_STRICT</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$mysqli&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">mysqli</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"world"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$city&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">"Amersfoort"</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">/*&nbsp;create&nbsp;a&nbsp;prepared&nbsp;statement&nbsp;*/<br /></span><span style="color: #0000BB">$stmt&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$mysqli</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">stmt_init</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">prepare</span><span style="color: #007700">(</span><span style="color: #DD0000">"SELECT&nbsp;District&nbsp;FROM&nbsp;City&nbsp;WHERE&nbsp;Name=?"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;bind&nbsp;parameters&nbsp;for&nbsp;markers&nbsp;*/<br /></span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">bind_param</span><span style="color: #007700">(</span><span style="color: #DD0000">"s"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$city</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;execute&nbsp;query&nbsp;*/<br /></span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">execute</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/*&nbsp;bind&nbsp;result&nbsp;variables&nbsp;*/<br /></span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">bind_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$district</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;fetch&nbsp;value&nbsp;*/<br /></span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">fetch</span><span style="color: #007700">();<br /><br /></span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"%s&nbsp;is&nbsp;in&nbsp;district&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$city</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$district</span><span style="color: #007700">);</span>
</span>
</code></div>
   </div>

   <div class="example-contents"><p>过程化风格</p></div>
   <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /><br />mysqli_report</span><span style="color: #007700">(</span><span style="color: #0000BB">MYSQLI_REPORT_ERROR&nbsp;</span><span style="color: #007700">|&nbsp;</span><span style="color: #0000BB">MYSQLI_REPORT_STRICT</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$link&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">mysqli_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_user"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"my_password"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"world"</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$city&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">"Amersfoort"</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">/*&nbsp;create&nbsp;a&nbsp;prepared&nbsp;statement&nbsp;*/<br /></span><span style="color: #0000BB">$stmt&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">mysqli_stmt_init</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">mysqli_stmt_prepare</span><span style="color: #007700">(</span><span style="color: #0000BB">$stmt</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"SELECT&nbsp;District&nbsp;FROM&nbsp;City&nbsp;WHERE&nbsp;Name=?"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;bind&nbsp;parameters&nbsp;for&nbsp;markers&nbsp;*/<br /></span><span style="color: #0000BB">mysqli_stmt_bind_param</span><span style="color: #007700">(</span><span style="color: #0000BB">$stmt</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"s"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$city</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;execute&nbsp;query&nbsp;*/<br /></span><span style="color: #0000BB">mysqli_stmt_execute</span><span style="color: #007700">(</span><span style="color: #0000BB">$stmt</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;bind&nbsp;result&nbsp;variables&nbsp;*/<br /></span><span style="color: #0000BB">mysqli_stmt_bind_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$stmt</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$district</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;fetch&nbsp;value&nbsp;*/<br /></span><span style="color: #0000BB">mysqli_stmt_fetch</span><span style="color: #007700">(</span><span style="color: #0000BB">$stmt</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"%s&nbsp;is&nbsp;in&nbsp;district&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$city</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$district</span><span style="color: #007700">);</span>
</span>
</code></div>
   </div>

   <div class="example-contents"><p>以上例程会输出：</p></div>
   <div class="example-contents screen">
<div class="cdata"><pre>
Amersfoort is in district Utrecht
</pre></div>
   </div>
  </div>
 </div>


 <div class="refsect1 seealso" id="refsect1-mysqli-stmt.prepare-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="mysqli.stmt-init.html" class="function" rel="rdfs-seeAlso">mysqli_stmt_init()</a> - 初始化一条语句并返回一个用于mysqli_stmt_prepare(调用)的对象</span></li>
    <li class="member"><span class="function"><a href="mysqli-stmt.execute.html" class="function" rel="rdfs-seeAlso">mysqli_stmt_execute()</a> - Executes a prepared statement</span></li>
    <li class="member"><span class="function"><a href="mysqli-stmt.fetch.html" class="function" rel="rdfs-seeAlso">mysqli_stmt_fetch()</a> - Fetch results from a prepared statement into the bound variables</span></li>
    <li class="member"><span class="function"><a href="mysqli-stmt.bind-param.html" class="function" rel="rdfs-seeAlso">mysqli_stmt_bind_param()</a> - Binds variables to a prepared statement as parameters</span></li>
    <li class="member"><span class="function"><a href="mysqli-stmt.bind-result.html" class="function" rel="rdfs-seeAlso">mysqli_stmt_bind_result()</a> - Binds variables to a prepared statement for result storage</span></li>
    <li class="member"><span class="function"><a href="mysqli-stmt.get-result.html" class="function" rel="rdfs-seeAlso">mysqli_stmt_get_result()</a> - Gets a result set from a prepared statement as a mysqli_result object</span></li>
    <li class="member"><span class="function"><a href="mysqli-stmt.close.html" class="function" rel="rdfs-seeAlso">mysqli_stmt_close()</a> - Closes a prepared statement</span></li>
   </ul>
  </p>
 </div>


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